1. Field of the Invention
The present invention relates to a sheet conveying device that conveys sheets, and a sheet discharging device using the sheet conveying device and an image forming apparatus using the sheet conveying device or the sheet discharging device.
2. Description of the Related Art
Image forming apparatuses, such as copying machines, printing machines, facsimile machines, and multifunction peripherals having two or more functions of these machines, have a problem that when the apparatus discharges a media sheet (hereinafter, “sheet”), a leading end of the sheet can be drooped and bent, resulting in improper stacking on a sheet output tray. This can occur particularly when the discharged sheet is a thin paper sheet or a large-size paper sheet.
There are conventionally proposed techniques for solving such a problem. In the techniques, when a sheet is discharged, the sheet is bended in its thickness direction to provide rigidity to the sheet.
For instance, in Japanese Laid-open Patent Application No. 2005-263418, there is disclosed a configuration including a rigidity-providing member that lifts up a widthwise center portion of a sheet being discharged. Because rigidity is provided to the sheet by elastically bending the sheet in a manner to lift up the widthwise center portion of the sheet, the sheet can be discharged onto a sheet output tray without being bent at a leading end of the sheet.
In Japanese Patent No. 4889805 or Japanese Laid-open Patent Application No. 2010-6538, there is disclosed a configuration that includes rigidity-providing rollers (or a rigidity-providing ring) that are larger in diameter than conveying rollers. A sheet is provided rigidity by elastically bending the sheet in its thickness direction using the rigidity-providing rollers.
However, such the configurations disclosed in Japanese Laid-open Patent Application No. 2005-263418, Japanese Patent No. 4889805, and Japanese Laid-open Patent Application No. 2010-6538 have the following disadvantages. When excessive elastic bending is performed on a sheet (in particular, a thick sheet) being conveyed, the sheet can be damaged by indentation left by the elastic bending and/or friction. As a result, image quality can disadvantageously decline.
In light of the circumstance, there is a need to provide a sheet conveying device capable of lessening damage to a recording sheet-like medium (a sheet) such as a paper sheet or the like, and a sheet discharging device using the sheet conveying device and image forming apparatus using the sheet conveying device or the sheet discharging device.
It is an object of the present invention to at least partially solve the problems in the conventional technology.